Or a Simple CASE expression. Below is the example MS-SQL code: @Order is set to 1 and as first WHEN Boolean expression evaluates to TRUE, Tutorial_ID is selected for Order by Condition, Copyright - Guru99 2023 Privacy Policy|Affiliate Disclaimer|ToS, Difference between Simple and searched case, Oracle vs SQL Server Difference Between Them, What is SQL Server? WHERE expression comparison_operator [ANY | ALL] (subquery), ALL [>ALL or ALL operator takes the list of values produced by the inner query and fetches all the values which are greater than the maximum of the list. In some situations, an expression is evaluated before a CASE expression receives the results of the expression as its input. If no conditions are true, it will return the value in the ELSE clause. Learn more about this powerful statement in this article. input_expression is any valid expression. CASE statement in SQL procedures CASE statements can be used to conditionally enter into some logic based on the status of a condition being satisfied. ELSE NUMEROTELEFONO Returns the result_expression of the first input_expression = when_expression that evaluates to TRUE. Because the subquery may be evaluated once for each row processed by the outer query, it can be slow. Why is this sentence from The Great Gatsby grammatical? Is there a proper earth ground point in this switch box? If no conditions are true, it returns the value in the ELSE clause.. Jordan's line about intimate parties in The Great Gatsby? As an example, say we had a table with 2 integer fields, column a and column b. ELSE 0 END as Qty. http://msdn.microsoft.com/en-us/library/ms181765.aspx, How Intuit democratizes AI development across teams through reusability. Do I need a thermal expansion tank if I already have a pressure tank? ic.product_type = Graphics I think the AVG function and the COUNT might make it impossible. Your article is the most complete I have found on the internet discussing CASE. In this article, we would explore the CASE statement and its various use cases. ncdu: What's going on with this second size column? We need to make an alias of the subquery because a query needs a table object which we will get from making an alias for the subquery. If you want to use the alias (the AS prod part) in the GROUP BY, you cant do this in the same query. My question is if you can use the SAME CASE statement in both places in the SAME query, with one referencing the other. Within a SELECT statement, the searched CASE expression allows for values to be replaced in the result set based on comparison values. How can I do an UPDATE statement with JOIN in SQL Server? There is a way to do this though. It returns a corresponding value associated with the condition defined by the user. The SQL CASE statement allows you to perform IF-THEN-ELSE functionality within an SQL statement. ) union all Not the answer you're looking for? By rejecting non-essential cookies, Reddit may still use certain cookies to ensure the proper functionality of our platform. Hi Claudia, are you running this on SQL*Plus? FROM A001470.PRODUCTOADQUIRIDO PA Doesn't the inner select statement create a result set which the outer SELECT statement then queries? In Simple Case, VALUE exists for each WHEN statement. This means that each expression in the WHEN section is evaluated individually. The data types of else_result_expression and any result_expression must be the same or must be an implicit conversion. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. A simple expression to which input_expression is compared when the simple CASE format is used. Is it possible to rotate a window 90 degrees if it has the same length and width? (SELECT * Lets have a look at SIMPLE CASE example below: Here, Tutorial_name is a part of CASE expression in SQL. And tl.entity_id = wi.entity_id Why do small African island nations perform better than African continental nations, considering democracy and human development? SELECT CASE Expression. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Simple Case support only equality check. Hi Ben! I created some test data and it seemed to work for me with a performance improvement. If all result expressions use the NULL constant, error 8133 is returned. Why do small African island nations perform better than African continental nations, considering democracy and human development? This happens for both Simple and Searched expressions. met (like an if-then-else statement). However, it uses an IN clause, which means the value is checked to see if it is in the IN parameter. CASE your_case_criteria AS prod If Boolean_expression_1 is FALSE, then Boolean_expression_2 is evaluated for TRUE condition. We can nest CASE statements similar to nested ifs that we find in most programming languages. A common question on SQL CASE statements is if the database evaluates all of the conditions in the CASE statement, or does it stop after finding the first match? Add a column with a default value to an existing table in SQL Server, How to concatenate text from multiple rows into a single text string in SQL Server. cant i use case within case like below, it says column does not exsist? ) WHEN USA THEN 1 SELECT ITEM ,DETAIL_LEVEL_DESC AS DESCRIPTION ,COMP_DETAIL_ID AS PROMO_ID ,CASE WHEN CHANGE_TYPE = 'N' THEN CASE WHEN INSTR (UPPER (DETAIL_LEVEL_DESC), 'S/P')!=0 THEN 'SPP' This article applies to Oracle, SQL Server, MySQL, and PostgreSQL. i have employee table with column id, name, dept, salary WHEN MILITARY_STATUSES = RAIR,RARMY,RCG,RMAR,RNAVY,RNG Aggregate expressions that appear in WHEN arguments to a CASE expression are evaluated first, then provided to the CASE expression. ;-), Your two code snipets betwen THEN/ELSE and ELSE/END appear the same? The Case_Expression is compared with Value, in order starting from the first value, i.e., Value_1. [ ELSE else_expression ] END Parameters boolean_expression ORDER BY first_name, last_name; Again, I recognize you wouldn't write this exact query. WHEN MILITARY_STATUSES (AMAR,DODMA,FAMMA,RMAR,VMAR) ORDER BY first_name, last_name; then the so called the column alias Continent is truncated to Con. Very Informative. OR (g.cell_id IS NULL AND :P835_STATE IN (%,MP)) ELSE NULL AND PERMIL_PRIMARY_FLAG=YES); Hi Deborah, I think this is because of the * character before the case. : Before formatting: SELECT DISTINCT c. LastName a , c. FirstName b After formatting, indent for 0 spaces: LearnSQL.com allows you to choose from a full learning track, mini-tracks to sharpen targeted skills, and individual courses. How would you guys write it as a generic template. THEN ANG For example, some customers may have both <1 employees and <10 employees. In a SQL database query, a correlated subquery (also known as a synchronized subquery) is a subquery (a query nested inside another query) that uses values from the outer query. If youre just using standard SQL in your application or database, then you can use the CASE statement. Else contain Nested CASE Statement in SQL inside it. CASE country SUM(count_hist) AS count_hist It is also possible to use it with SET, IN, HAVING, ORDER BY and WHERE. I.e. (SELECT C_ID from COURSE where C_NAME = 'DSA' or C_NAME ='DBMS'); The inner query will return a set with members C1 and C3 and outer query will return those S_ID s for . SQL HOME SQL Intro SQL Syntax SQL Select SQL Select Distinct SQL Where SQL And, Or, Not SQL Order By SQL Insert Into SQL Null Values SQL Update SQL Delete SQL Select Top SQL Min and Max SQL Count, Avg, Sum SQL Like SQL Wildcards SQL In SQL Between SQL Aliases SQL Joins SQL Inner Join SQL Left Join SQL Right Join SQL Full Join SQL Self Join SQL . Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. The Boolean expression evaluated when using the searched CASE format. else_result_expression is any valid expression. WHEN MILITARY_STATUSES = VAIR,VANG,VARM,VCG,VMAR,VNAVY,VNG You have IF, ELSE, ELSIF and END. The CASE expression evaluates its conditions sequentially and stops with the first condition whose condition is satisfied. What is the correct way to screw wall and ceiling drywalls? SUM(count_topo) AS count_topo, ESTADOPROVISIONAMIENTO AS ESTADO, INNER JOIN item_class_data ic ON g.itcl_id = ic.id Is it a bug? It comes in two formats: simple case search case Simple SQL CASE Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. The following example uses the CASE expression in a SET statement in the table-valued function dbo.GetContactInfo. This occurs prior to evaluating the CASE expression. (select 1 seq,trunc(avg(count)) Avg from (select to_char(dldate,YYYY-MM), count(*) count from GRAPHICS_DOWNLOAD g where itcl_id Yes, you can use a CASE within CASE in SQL. The value can be a literal or an expression. Is it suspicious or odd to stand by the gate of a GA airport watching the planes? in SQL CASE provides the author of the query with the ability to perform conditional logic in their SQL queries for SELECT, INSERT, UPDATE, DELETE. For example, the person may be an employee, vendor representative, or a customer. ic.product_theme Its quite common if youre writing complicated queries or doing any kind of ETL work. Is there a proper earth ground point in this switch box? The maximum number of conditions in a CASE statement is 255. The examples below will show how this is done. If there is no result, and there is no ELSE statement, then the value of NULL is returned. CASE WHEN THEN Statement_1, E.g. Ive had a look at your query and yes I think it can be improved with CASE. How can I explain to my manager that a project he wishes to undertake cannot be performed by the team? No problem Margaret, it was a good challenge for me! if x.boy is not null then x.boy else if x.girl is not null then x.girl else if x.dog is not null then x.dog else x.cat Bulk update symbol size units from mm to map units in rule-based symbology. condN: A BOOLEAN expression. Connect and share knowledge within a single location that is structured and easy to search. ) If there is no ELSE part and no conditions are true, it returns NULL. : And I had never used UNPIVOT. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. FROM ( I know to use case when condition then X else y end but how do you do a nested one in the same fashion for each record in a record set. Connect and share knowledge within a single location that is structured and easy to search. Theoretically Correct vs Practical Notation. Below is the execution approach: If Case_Expression is equivalent to Value_1, then further WHENTHEN statements are skipped, and CASE execution will END immediately. INNER JOIN A001470.CUENTAFACTURACION CF What video game is Charlie playing in Poker Face S01E07? However, you can use a native SQL statement to achieve the same goal. I know to use case when condition then X else y end but how do you do a nested one in the same fashion for each record in a record set. Is it plausible for constructed languages to be used to affect thought and control or mold people towards desired outcomes? The statement returns the hourly rate for each job title in the HumanResources.Employee table. END) as prod, SQL Server Case Statement. The CASE expression in the SET statement determines the value to display for the column ContactType based on the existence of the BusinessEntityID column in the Employee, Vendor, or Customer tables. CASE country E.g., Visitor will perform the act of visiting New York only in the condition if the flight ticket is between $100 to $200. A subquery is a SELECT statement that is nested within another SELECT statement and which return intermediate results. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, My answer has a few different ways to write your statement that are correct. Am I missing something? The result gets evaluate for the TRUE/FALSE condition for each WHEN Statement. THEN RES If no conditions are true, it returns the value in the ELSE clause. Programmatic interfaces for the case when in select statement in sql select, then oracle is sql join and analysis. How Intuit democratizes AI development across teams through reusability. Below is the example MS-SQL code: In the above example CASE is used in the UPDATE statement. When expression1 Then Result1. The CASE expression can't be used to control the flow of execution of Transact-SQL statements, statement blocks, user-defined functions, and stored procedures. ELSE Result. Find centralized, trusted content and collaborate around the technologies you use most. OR :P835_STATE=% If Case_Expression does not match with Value_1, then Case_Expression is compared with Value_2 for equivalency. T-SQL CASE Clause: How to specify WHEN NULL, OR is not supported with CASE Statement in SQL Server, TSQL CASE with if comparison in SELECT statement. In addition to SELECT, CASE can be used with another SQL clause like UPDATE, ORDER BY. The expression evaluated when the simple CASE format is used. ( Ob Long; Position; Hacker Database. SELECT CASE WHEN score >= 60 THEN "passed" ELSE "failed" END AS result, COUNT(*) AS number_of . CASE is one of the most powerful and more complex built-in expressions in Transact-SQL. A simplified example: SELECT col1, col2, col3, CASE WHEN condition THEN CASE WHEN condition1 THEN CASE WHEN condition2 THEN calculation1 ELSE calculation2 END ELSE CASE WHEN condition2 THEN calculation3 ELSE calculation4 END END ELSE CASE WHEN condition1 THEN CASE WHEN condition2 THEN calculation5 ELSE calculation6 END ELSE CASE WHEN condition2 . I want to redo the following using CASE. SQL Server allows for only 10 levels of nesting in CASE expressions. This example uses the MOD function to demonstrate how you can use CASE statements with functions. Like Simple Case ELSE is optional in Search case as well. About an argument in Famine, Affluence and Morality. first_name, last_name, country, Asking for help, clarification, or responding to other answers. WHEN France THEN Europe Within a SELECT statement, the CASE expression allows for values to be replaced in the result set based on comparison values. I am trying to select only certain columns from a table but need to read in these columns based on conditions of other columns that I DON'T want to include in the final output - if that makes any sense. and t1.entity_id = ued.entity_id THEN AF The nature of simulating nature: A Q&A with IBM Quantum researcher Dr. Jamie We've added a "Necessary cookies only" option to the cookie consent popup. txn_logs tl, We can see that the results show different values based on the nested CASE statement. Statements that include a subquery usually take one of these forms: Check for more subquery rules and subquery types. The CASE expression is a conditional expression, similar to if/then/else statements found in other languages. Two or from GRAPHICS_DOWNLOAD g where itcl_id ( If you want to use IF logic, then use the CASE statement. Hello! Find centralized, trusted content and collaborate around the technologies you use most. Else, I will prefer to visit some nearby tourist spot. I know you can use the CASE statement in either. SELECT columms, Add a column with a default value to an existing table in SQL Server, How to check if a column exists in a SQL Server table, How to concatenate text from multiple rows into a single text string in SQL Server, LEFT JOIN vs. LEFT OUTER JOIN in SQL Server. Learn how your comment data is processed. Ill demonstrate this using more examples later in this article. Only one condition can be true. It checks the number of employees and determines if they have an odd or even number of employees. current_page_url ilike %optus.com.au/shop/entertainment% OR rev2023.3.3.43278. dl_month, group by to_char(dldate,YYYY-MM))) d What happens here? WHEN MILITARY_STATUSES (AAIR,DODAF,FAMAF,RAIR,VAIR) As the data for columns can vary from row to row, using a CASE SQL expression can help make your data more readable and useful to the user or to the application. In MS SQL, there are two types of CASE: Simple CASE and Searched CASE. ELSE NUMEROTELEFONO The CASE statement should exit when it reaches the first TRUE condition. WHERE PER_MILITARY_ID=MILITARY_ASSOC.ID Thanks for contributing an answer to Stack Overflow! On Contrary, SEARCH CASE example has no CASE Expression: Here, each WHEN statement has its Conditional Boolean expression. SQL> select emp_name , case when Salary < 10000 then 'Junior Level' when (Salary >=10000 and Salary < 50000) then 'Middle Level' when (Salary >= 50000 and Salary < 100000) then 'Senior Level' else (Case when grade ='20' then 'Vice President' when grade='21' then . A useful function in SQL is creating a query within a query, also known as a subquery or nested query. If so, it should be SELECT *, (CASE WHEN Add the comma after *. THEN CG Statement(s) could not be prepared. expr: Any expression for which comparison is defined. (AVG(NULLIF(count_scan_map, 0))) AS avg_scanmap, Santa Claus Old; Parental Ny; Buts. However, SQL isnt like other programming languages. It takes about 95 seconds to load on my machine. but an approach that may work is selecting only the simple-name records and then a nested SELECT expression that will count all records with that name. Theoretically Correct vs Practical Notation. MySQL has a DECODE function but its used for something completely different. Yes. The CASE statement goes through conditions and return a value when the first condition is met (like an IF-THEN-ELSE statement). Although, here is your script, written corectly: although you could just use coalesce as Joe suggested. FROM Your explanations are really helpfull but i still cant make work this query. I'm sure it's probably pretty simple but can't see what's wrong. How do I perform an IFTHEN in an SQL SELECT? In ApexSQL Refactor in the Lists tab under the Columns sub-tab, formatting options can be combined for data statements formatting such as Select, Insert etc. Does Counterspell prevent from any further spells being cast on a given turn? This EXISTS checks the existence of the rows returned by the sub query. If ELSE is not present and Case_Expression matches with none of the values, then. : where ic.product_type in (Graphics) and ic.product_theme=Hist) case-operand. To learn more, see our tips on writing great answers. where dt between 2018-06-15 and 2018-07-17 The OUTPUT clause is used to display the before and after vacation values. FROM customers How do I align things in the following tabular environment? If flight tickets are between $100 to $200, then I will visit New York, If flight tickets are between $200 to $400, then I will visit Europe. In the first example, the value in the SalariedFlag column of the HumanResources.Employee table is evaluated. Thanks for contributing an answer to Stack Overflow! 163 Jordan's line about intimate parties in The Great Gatsby? Notify me of follow-up comments by email. CASE WHEN sub.product_theme = Hist AND sub.itcl_id != 163 THEN 1 ELSE 0 END count_hist You should only depend on order of evaluation of the WHEN conditions for scalar expressions (including non-correlated subqueries that return scalars), not for aggregate expressions. Arguments. CASE WHEN THEN Statement_1 In above example, Boolean_Expression_1 can contain both equal to and not equal to operator like A = B, A != B. INNER JOIN A001470.INDIVIDUOCUENTACLIENTE ICC CASE t_wm_wallet_info wi, t_um_entity_detail ued Privacy Policy. I moved a copy of the database from production DB (SQL 2005) to my local machine running SQL 2008, and then indexed the copy of the database. More info about Internet Explorer and Microsoft Edge. CASE can be used in any statement or clause that allows a valid expression. A case expression allows the user to use IF - THEN - ELSE logic without using procedures in SQL statements. Ultimately, if you like nested IF() functions and they don't upset your co-workers, keep doing your thing. What is the point of Thrower's Bandolier? >>I'm having trouble getting a CASE statement to work in a nested select.<< What trouble do you have? Hopefully my SQL query will clear up what I'm trying to do: SELECT dateOfBooking, amORpm, conferenceRoomID, noDelegates, cateringInfo, allergyInfo, specialAccessInfo, bottledWaterNeeded, projectorNeeded, lecternNeeded FROM ( SELECT * FROM dbo.tableBookingSlots WHERE bookingID . Evaluates, in the order specified, Boolean_expression for each WHEN clause. The syntax of the CASE . AND cs.name LIKE %||:P835_STATE||% Can airtags be tracked from an iMac desktop, with no iPhone? more expressions may be combined together using the logical dl_month, Is it suspicious or odd to stand by the gate of a GA airport watching the planes? Afterwards I illustrate the functionality using a practical example. ) By accepting all cookies, you agree to our use of cookies to deliver and maintain our services and site, improve the quality of Reddit, personalize Reddit content and advertising, and measure the effectiveness of advertising. Let's do a bit of different analysis on these data. group by to_char(dldate,YYYY-MM))) d SELECT When expression2 Then Result2. Depending upon Flight ticket value, one amongst the following result will be displayed: We can use CASE inside CASE in SQL. For a list of control-of-flow methods, see Control-of-Flow Language (Transact-SQL). So, once a condition is true, it will stop reading and return the result. Making statements based on opinion; back them up with references or personal experience. and our If Flight_Ticket < $400 then inner CASE will execute. ELSE NULL You did it all without any UNIONs. The first takes a variable called case_value and matches it with some statement_list. (CASE WHEN current_page_url %optus.com.au/shop/broadband/nbn% THEN Fixed_NBN INNER JOIN A001470.INDIVIDUO I ON ICF.IDINDIVIDUO = I.IDINDIVIDUO resN: Any expression that has a least common type with all other resN and def. The parameters or components of the CASE SQL statement are: There are actually two ways to use an SQL CASE statement, which are referred to as a simple case expression or a searched case expression. Exclude a column using SELECT * [except columnA] FROM tableA? Then Tutorial_name value is compared with each WHEN values, i.e. The nature of simulating nature: A Q&A with IBM Quantum researcher Dr. Jamie We've added a "Necessary cookies only" option to the cookie consent popup. Select * means select all columns, but then you have a CASE statement. Thats strange the second CASE is being ignored. So, how can you have an SQL IF statement? What's the difference between a power rail and a signal line? SELECT Msg 125, Level 15, State 4, Line 1. This example shows all customerswho live inNorth America, using the CASE statement to restrict the records. (in the example above, the case results are captured as prod ). WHEN UK THEN Europe The following example displays the list price as a text comment based on the price range for a product. We can write this code using SQL IIF statement syntax as following. THEN NAVY New to PL/SQL in Oracle9 i, the CASE statement allows you to select one sequence of statements to execute out of many possible sequences. Below Diagram illustrate the execution flow of the Searched Case. A subquery may occur in : - A SELECT clause - A FROM clause - A WHERE clause The subquery can be nested inside a SELECT, INSERT, UPDATE, or DELETE statement or inside another subquery. WHEN current_page_url %optus.com.au/shop/broadband/mobile-broadband% THEN Fixed_MBB Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness of all content. Good question. How can I explain to my manager that a project he wishes to undertake cannot be performed by the team? SQL has an ability to nest queries within one another. Is it possible to use the same CASE statement for both the SELECT clause and the WHERE clause? Is it possible to create a concave light? WHEN MILITARY_STATUSES = DODAF, DODAG,DODAR,DODCG,DODMA,DODNA,DODNG Exclude a column using SELECT * [except columnA] FROM tableA? A simple example: If thats the message youre getting, which column does it say does not exist? Using Kolmogorov complexity to measure difficulty of problems? CASE can be nested in another CASE as well as in another IFELSE statement. How do I UPDATE from a SELECT in SQL Server? The system will print Visit Nearby Tourist Location if flight tickets are > $400, The system will print Visit Los Angeles if flight tickets are BETWEEN $0 AND $100, The system will print Visit New York if flight tickets are BETWEEN $101 AND $200, The system will print Visit Europe if flight tickets are BETWEEN $201 AND $400, If Tutorial_Name = SQL THEN update Tutorial_Name to Structured Query language, If Tutorial_Name = PL/SQL THEN update Tutorial_Name to Oracle PL/SQL, If Tutorial_Name = MSSQL THEN update Tutorial_Name to Microsoft SQL, If Tutorial_Name = Hadoop THEN update Tutorial_Name to Apache Hadoop. A place where magic is studied and practiced? FROM ( So, once a condition is true, it will stop reading and return the result. The data types of input_expression and each when_expression must be the same or must be an implicit conversion. Other than that, you just need. As we need a table object in the outer query, we need to make an alias of the inner query. Helped me tremendously. Minimising the environmental effects of my dyson brain. when ued.user_type in (85,73,74) then t2.amt_type in (TXN_AMT,COMM) else t2.amt_type =TXN_AMT end case, Write a query to display EMPLOYEES having ID 101,102,103 as per the You can use the SELECT with the CASE and all its clauses as a subquery, then in the outer query use the GROUP BY. CASE This means the WHEN expressions are all compared to that field. Does a barbarian benefit from the fast movement ability while wearing medium armor? Also, the keyword ilike should be like to use wildcard searches. Nested Oracle Case statement. Thank you very much, The HAVING clause restricts the titles to those that are held by salaried employees with a maximum pay rate greater than 40 dollars, or non-salaried employees with a maximum pay rate greater than 15 dollars. (CASE error (incorrect syntax near CASE, expecting ( or SELECT) It finds the first match, or the first expression that is evaluated to be a match, and does not continue with the rest. WHEN MILITARY_STATUSES (AARMY,DODAR,FAMAR,RARMY,VARM) The SQL CASE Expression The CASE expression goes through conditions and returns a value when the first condition is met (like an if-then-else statement). Select S_ID from STUDENT_COURSE where C_ID IN. Boolean_expression is any valid Boolean expression. GROUP BY dl_month Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, Make sure your alias is somewhat verbose too! EXISTS ( FROM yourtable; This will show even values in one column, odd values in another. In Searched Case, Boolean_Expression exists for each WHEN statement. Any Errors or Warnings? What can a lawyer do if the client wants him to be acquitted of everything despite serious evidence? g.cell_id, When case-operand is specified, when-condition is a shortened sql-expression that assumes case-operand as one of its operands and that resolves to true or false.. Find all tables containing column with specified name - MS SQL Server, Partner is not responding when their writing is needed in European project application. Is it suspicious or odd to stand by the gate of a GA airport watching the planes? What is the purpose of this D-shaped ring at the base of the tongue on my hiking boots? The CASE statement finds the first matching expression and uses that. Query 2: SEARCHED CASE with the ELSE option. Don't mistake CASE for the IF ELSE control of flow construct, which is used to evaluate the conditional execution of SQL statements. This example performs a searched CASE using a number field, which is the number of employees. and wi.wallet_type = 1 If they all are numeric, then the database will determine which argument has the highest numeric precedence, implicitly convert the remaining argument to that data type, and return that datatype. To learn more, see our tips on writing great answers. Hi Margaret, so i want sal which has greater than avg(sal) ,if sal >avg(sal) then give flag Y other wise N? It offers multiple hands-on interactive SQL courses with exercises to cover nested SELECT statements and other challenging SQL features.